package cn.myweixin.util;
import java.awt.image.BufferedImage;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileNotFoundException;  
import java.io.IOException;  
import java.io.InputStream;  
import java.util.HashMap;  
import java.util.Iterator;  
import java.util.Map;  
import java.util.Map.Entry;  


public class FileTypeUtil {

	 public final static Map<String, String> FILE_TYPE_MAP = new HashMap<String, String>();    
     
	    private FileTypeUtil(){}    
	    static{    
	        getAllFileType();  //初始化文件类型信息    
	    }    
	        
	    /**  
	     * Created on 2010-7-1   
	     * <p>Discription:[getAllFileType,常见文件头信息]</p>  
	     * @author:[shixing_11@sina.com]  
	     */    
	    private static void getAllFileType()    
	    {    
	        FILE_TYPE_MAP.put("jpg", "FFD8FF"); //JPEG (jpg)    
	        FILE_TYPE_MAP.put("png", "89504E47");  //PNG (png)    
	        FILE_TYPE_MAP.put("gif", "47494638");  //GIF (gif)    
	        FILE_TYPE_MAP.put("tif", "49492A00");  //TIFF (tif)    
	        FILE_TYPE_MAP.put("bmp", "424D"); //Windows Bitmap (bmp)    
	        FILE_TYPE_MAP.put("dwg", "41433130"); //CAD (dwg)    
	        FILE_TYPE_MAP.put("html", "68746D6C3E");  //HTML (html)    
	        FILE_TYPE_MAP.put("rtf", "7B5C727466");  //Rich Text Format (rtf)    
	        FILE_TYPE_MAP.put("xml", "3C3F786D6C");    
	        FILE_TYPE_MAP.put("zip", "504B0304");    
	        FILE_TYPE_MAP.put("rar", "52617221");    
	        FILE_TYPE_MAP.put("psd", "38425053");  //Photoshop (psd)    
	        FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A");  //Email [thorough only] (eml)    
	        FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F");  //Outlook Express (dbx)    
	        FILE_TYPE_MAP.put("pst", "2142444E");  //Outlook (pst)    
	        FILE_TYPE_MAP.put("xls", "D0CF11E0");  //MS Word    
	        FILE_TYPE_MAP.put("doc", "D0CF11E0");  //MS Excel 注意：word 和 excel的文件头一样    
	        FILE_TYPE_MAP.put("mdb", "5374616E64617264204A");  //MS Access (mdb)    
	        FILE_TYPE_MAP.put("wpd", "FF575043"); //WordPerfect (wpd)     
	        FILE_TYPE_MAP.put("eps", "252150532D41646F6265");    
	        FILE_TYPE_MAP.put("ps", "252150532D41646F6265");    
	        FILE_TYPE_MAP.put("pdf", "255044462D312E");  //Adobe Acrobat (pdf)    
	        FILE_TYPE_MAP.put("qdf", "AC9EBD8F");  //Quicken (qdf)    
	        FILE_TYPE_MAP.put("pwl", "E3828596");  //Windows Password (pwl)    
	        FILE_TYPE_MAP.put("wav", "57415645");  //Wave (wav)    
	        FILE_TYPE_MAP.put("avi", "41564920");    
	        FILE_TYPE_MAP.put("ram", "2E7261FD");  //Real Audio (ram)    
	        FILE_TYPE_MAP.put("rm", "2E524D46");  //Real Media (rm)    
	        FILE_TYPE_MAP.put("mpg", "000001BA");  //    
	        FILE_TYPE_MAP.put("mov", "6D6F6F76");  //Quicktime (mov)    
	        FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); //Windows Media (asf)    
	        FILE_TYPE_MAP.put("mid", "4D546864");  //MIDI (mid)    
	    }    
	    
	    public static void main(String[] args) throws Exception    
	    {    
	        File f = new File("C:/Users/m/Desktop/sample.pdf");   
	        File f1 = new File("C:/Users/m/Desktop/新建文本文档.txt");  
	     
	            String filetype1 = getFileByFile(f);   
	            if(filetype1=="pdf"){
	            System.out.println("yes");   } 
	            else
	            { System.out.println("no");
	            }
	         
	            
	      
	    }    
	    
	
	    
	    /**  
	     * Created on 2010-7-1   
	     * <p>Discription:[getFileByFile,获取文件类型,包括图片,若格式不是已配置的,则返回null]</p>  
	     * @param file  
	     * @return fileType  
	     * @author:[shixing_11@sina.com]  
	     */    
	    public final static String getFileByFile(File file)    
	    {    
	        String filetype = null;    
	        byte[] b = new byte[50];    
	        try    
	        {    
	            InputStream is = new FileInputStream(file);    
	            is.read(b);    
	            filetype = getFileTypeByStream(b);    
	            is.close();    
	        }    
	        catch (FileNotFoundException e)    
	        {    
	            e.printStackTrace();    
	        }    
	        catch (IOException e)    
	        {    
	            e.printStackTrace();    
	        }    
	        return filetype;    
	    }    
	        
	    /**  
	     * Created on 2010-7-1   
	     * <p>Discription:[getFileTypeByStream]</p>  
	     * @param b  
	     * @return fileType  
	     * @author:[shixing_11@sina.com]  
	     */    
	    public final static String getFileTypeByStream(byte[] b)    
	    {    
	        String filetypeHex = String.valueOf(getFileHexString(b));    
	        Iterator<Entry<String, String>> entryiterator = FILE_TYPE_MAP.entrySet().iterator();    
	        while (entryiterator.hasNext()) {    
	            Entry<String,String> entry =  entryiterator.next();    
	            String fileTypeHexValue = entry.getValue();    
	            if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {    
	                return entry.getKey();    
	            }    
	        }    
	        return null;    
	    }    
	        
	
	      
	    /**  
	     * Created on 2010-7-1   
	     * <p>Discription:[getFileHexString]</p>  
	     * @param b  
	     * @return fileTypeHex  
	     * @author:[shixing_11@sina.com]  
	     */    
	    public final static String getFileHexString(byte[] b)    
	    {    
	        StringBuilder stringBuilder = new StringBuilder();    
	        if (b == null || b.length <= 0)    
	        {    
	            return null;    
	        }    
	        for (int i = 0; i < b.length; i++)    
	        {    
	            int v = b[i] & 0xFF;    
	            String hv = Integer.toHexString(v);    
	            if (hv.length() < 2)    
	            {    
	                stringBuilder.append(0);    
	            }    
	            stringBuilder.append(hv);    
	        }    
	        return stringBuilder.toString();    
	    }    
	
	
}
